620 J. W. DAVIS ON REMAINS OF FOSSIL FISHES 
the lower massive limestone of Ireland, Derbyshire, in Northumber- 
land, and near Kendal; it has also been found in the Lower-lime- 
stone series of the west of Scotland. Specimens are usually found 
about 1 inch to 1°23 inch in breadth across the base, and with the 
central cusp about half an inch in height. The examples which 
have been found near Leyburn are not more than half the size of 
the above. The central cones are more or less striated, and the 
small lateral cones are numerous and arranged somewhat in clusters 
as in the type specimens ; they appear to indicate that this species, 
which must have been a formidable and destructive fish during the 
period occupied in the formation of the lower strata of the Mountain- 
limestone series, was generally becoming much less so, and the 
circumstances point to the inference that the species was ‘gradually 
approaching extinction. 
Genus Hewicrapoots, Davis, g. n. 
Tooth or jaw consisting of several rows of minute teeth. The 
latter are broad at the base, rapidly acuminate and ending in a 
pointed apex; the several bases apparently anchylosed. 
Heanciabopts unicuspipatts, Davis,sp.n. (Plate XXVIL. figs. 24, 
24 a.) 
Teeth. Apparently a portion of a jaw containing three rows of 
teeth placed one behind the other. There are six or seven teeth in 
each row; those behind are placed in apposition to those in the front 
row. ‘The teeth in each row are attached laterally and present the 
appearance of bemg anchylosed together. They are slightly less 
than 0-1 inch in breadth at their ‘base, short, triangular in out- 
line, and pointed at the apex. The points are worn, in some cases 
considerably ; they are coated with enamel, which exhibits traces of 
minute punctures. The bases of the pes teeth assume an even, 
very slightly concave form. 
This series of teeth approaches more aoe to those of the genus 
Cladodus than any other in the pointed form of their apices, but 
they diverge in not possessing lateral denticles, which the teeth of 
Cladodus do, and in the character of the bases of the teeth, which 
are never joined so closely together in Cladodus as they are in 
this genus. 
Reed collection, York Museum. 
Genus Pristictapopus, McCoy, British Palzozoie Fossils, p. 642 
(1854). 
PrisTicLaboDus DENTATUS, McCoy, / .c. p. 642, pl. de. fig. 2 (1854). 
(Plate XXVII. fig. 4.) 
Several specimens of this species have been discovered in Wens- 
leydale. The most perfect specimens afford no indication that 
lateral denticles have been present. The size of mature examples 
reaches nearly one inch and a half in breadth across the base, and 
three quarters of an inch in height. The teeth appear to be all 
